4mm Aquamarine Celsian Czech Glass Fire Polish Beads. The area now known as the Czech Republic has been a leader in the glass industry since the Middle Ages. Factories in the Czech Republic continue to produce the highest-quality and most innovative glass beads. Czech Glass can be easily distinguished from lower quality glass produced elsewhere. This difference is most easily observed in the consistency, quality and variety of color and finish, as well as the consistency and quality of cut and shape. The faceted round beads commonly known as "Fire Polish" are machine cut and then slightly melted to create smoother edges. Lead Free. Approximately 50 beads per strand.